CAUTION: the cookbook is a little unpolished, still, but should
not steer you far wrong. In particular, the night assistant will help
with setting up the guider and FLI camera, for which there is separate documentation
(see Palomar
Autoguider).

DBSP
AT_THE_TELESCOPE COOKBOOK:

Original document by Eric Bloemhof 1998,
updated/revised: August 2008, by Jeff Hickey. This update covers the new
blue camera (CCD23), the new Labview based GUI's for both cameras, and the new Turret control.
The VAX/Figaro based operating system is now completely obsolete. For
all Palomar instrument related questions please contact
P200 Instrument Support.

Despite its intended real-time usefulness, the COOKBOOK contains
nuggets of instrument theory here and there that might require some
time to digest...so of course a thorough reading in advance of the
observing run is recommended to avoid unpleasant surprises at the
telescope. (Failing this, night assistants carry extra Kleenex).
Note: as of 2005 Kleenex no longer necessary.

(A) AFTERNOON OF THE FIRST NIGHT: HARDWARE SETUP...

Get to the 200" no later than
2:00 PM on the afternoon of your first night to make contact with
the support engineer, Jeff Hickey and/or Rick Burruss. The support
engineer is on usually from noon to 10pm, and can normally be
found in the office adjoining the 200" control room.

Check the white board in the
control room to see if the DBSP has been filled with liquid
nitrogen. The dewars are topped off every 10-12 hours. The night
assistant and Palomar day crew are responsible for filling the
dewars, and logging fill times on the white board. Dewar status may
be seen by reading its temperature from the temperature GUI's
described below. The temperatures are typically 154 for the red
camera, and 163 for the blue camera

Check with the staff that the
correct dichroic has been installed (changes require taking
instrument off telescope, and are done only in the daytime; changing
from slit wheel to multislits is also a daytime operation). Your
green sheet information is in a logbook located on or near the DBSP
control computer desk.

Check that the correct gratings
are installed by asking the day crew, or checking the logbook.

Check that the grating tilts have
been set, by asking the day crew. The day crew should have set them
to the values requested on the green sheet you turned in prior to
observing.

Check that the
neutral-density-filter knob is set to 0 (it's at top center of
instrument in Cass cage, almost level with base of forks holding the
spectrograph, and has settings 0,1,2,3)...else an ND filter will be
inserted in front of the arc lamp (but not in the sky light path).

Check that the "dust covers"
are open (thin, black-anodized metal covers near the top of DBSP
that can be rotated by hand)...the day crew can show you where these
are.

Decide on a filter from the following table (most observers
do not use filters):

FILTER WHEELS

Blue Filters

Red Filters

Wheel

Designation

Code

Filter

Designation

Code

Filter

1 [a]

B0

0

Clear

R0

0

Clear

"

B1

1

Clear

R1

1

GG455 [b]

"

B2

2

GG495 [b]

R2

2

Clear

"

B3

3

-

R3

3

RG610 [b]

2

B4

4

-

R4

4

-

"

B5

5

-

R5

5

-

"

B6

6

-

R6

6

-

"

B7

7

-

R7

7

-

[a] normally installed in
spectrograph. [b] antireflection coated. [c] liquid filters are not
to be used.

The filters used to be moved
with the blue DBSP control box from the control room. Now (4/2007) all DBSP turret functions are controlled by the new LabVIEW based Turret GUI. The Blue control box is gone, more on this below. The Main GUI
shows the current filter wheel location for each light path.

Decide on a slit from the following table:

SLIT WHEEL (128 arcsec
slits)

Slit Width

Readout Index

0.5 arcsec

0

1.0 arcsec

1

1.5 arcsec

2

2.0 arcsec

3

4.0 arcsec

4

6.0 arcsec

5

8.0 arcsec

6

10 arcsec

7

In the past the slits were moved
with the DBSP blue control box. Now as with the filters, the slits are controlled with the new Turret GUI(see below). The Main GUI gives the current slit
location. See the section on the Main GUI.

In the picture below, one can see the VNC control window that has the DBSP Main and Turret GUI's. The Blue camera Main Gui is on the left. The Red camera Main GUI is on the right. And the Turret GUI is in the middle.

(B) AFTERNOON OF THE FIRST NIGHT:
DBSP Main GUI Interface

When you get to the 200" control room, DBSP and it's computer
workstation should already be set up. Usually a VNC window will be
open on a control room workstation linked to the DBSP computer on the
Mezzanine level. You should see two Main GUI windows on the VNC, one
for the red camera, and one for the blue camera. You will operate the
cameras using these two windows. Below is an image of the blue side
Main GUI. The Main GUI's are identical except that the colors are
different (red & blue), and the blue GUI has the sync option.
NOTE: Most of the following GUI information is stolen from (and more
detail can be found at) Marco Bonati's DBSP site;
http://www.astro.caltech.edu:8080/DETECT/palo_dbsp_blue/dbsp_soft_user_manual/dbsp_soft_user_manual

1.Main Graphic Interface window:

The
main window allows you to have general control of the camera. It has
a status area on the top part, and a control area on the bottom part
(the background color is slightly different for the status and
control area). The description below applies to both sides except as
mentioned above, the SYNC button, which is BLUE side only.

Status, The upper (light blue) area

1.- detstatus LEDs: There is one LED per detector status:
IDLE, PAUSED, EXPOSING and READING. This indicates what is the
current status of the detector.

2.- Links and Error LEDs: command, async: These 2 green
LEDs indicate if the client is fully connected to the Server. Both
LEDs should be green for having full-connection and functionality.
Error LED: this red LED will turn on when there is any status
condition (like a command that was not received, or an erroneous
response, etc).

3.- String status controls and progress bars immediate
response: This status shows the response from the server to ANY
requested action (EXPOSE, changing image parameter, etc). It will
normally be a DONE or ERROR <message>. If it there was an
error, the red error LED (2) will turn on, and the color of the error
message will also turn red on the control itself. async: this
will show any message that gets to the GUI asynchronously (not
necessarily related to a previously sent command). This messages can
be just an info (like "filter changed", or "image
expose is done"), or reporting a problem (like "TCS
connection lost", or "CCD temperature too high", etc).
aperture: shows the current aperture (in arcsec), read
asynchronously from the instrument when it changes. Be patient, this
status box takes a few seconds to update. filter: shows the
current filter position (filter name), read asynchronously from the
instrument when it changes. Be patient, this status box takes a few
seconds to update. image name: shows the name of the image
that will be (if exposing) , is (if writing), or was (if idle)
written to disk.

3.- Progress bars: read: this green bar shows the read
progress of the current image (in percentage). write: this
green bar shows the write progress of the current image (it is
normally written to disk as the image gets read). This will not move
if the image will not be written. sequence: this orange bar
shows the progress of the overall sequence. It will get to 100% only
when all the images of the sequence are done (which means that the
system is idle again)

4.- Exposure: This yellow, thick bar shows the exposure
progress. It can be seen (considering the system is linear) as a
"counts" progress. This shows the progress in seconds
rather than percentage (elapsed time). The upper limit will expand to
reflect the requested exposre time, so it will get full when the
requested exposure time is done, whatever that requested time was.

Control: The bottom (dark blue)
area.

All the controls can be changed while exposing. Right after the
exposure is done, and the readout begins, the current control values
are grabbed, so the final image will get those fields (like basename,
directory, type, etc).

5.- Image settings: Image path: this is the
directory where the images will be written. object: this is
the object name. This will appear on the OBJECT field of the fits
headers. observer : name of the observer (it will appear on
the OBSERVER field of the fits headers) exposure time : the
requested exposure time, in seconds (OEXPTIME of the image headers:
Original Exposure time). number of images : how many images to
take (sequence). write to disk: if checked, it will write the
images to disk. If unchecked, it will just read and display, but not
save to disk. obstype: observation type. This will appear on
the IMGTYPE field of the image headers. If "dark" is
selected, it will NOT open the shutter when the exposure starts.
basename: basename for the image. The image name is composed
by the basename and the image number as basename<number> (see
image number control). image number : it will create, together
with the basename, the final name of the image, using this rule:
basename%4d /*the numeric field will always have 4 places, so it will
fill with zeros to the left. For example, if the basename is "bias"
and the image number is 4, the final image written will be called
"bias0004". use type as basename: if checked, it
will change the basename to match the image type. For example, if
"object" is selected as image type, it will automatically
change the to "object" also

6.- Exposure commands/actions GO: it will
initiate the exposure. The "exposure" implies opening the
shutter, exposing by the seconds stated on the exposure time control,
close the shutter, and read/write the image with the specified name
(basename, image number) at the specified directory (image path); all
this as many times as the number of images control states. Pause:
This control has meaning only when exposing. If pulsed, it will
close the shutter and wait doing nothing. When the button is pulsed
again (resume) it will open the shutter and continue the exposure at
the stopped count. STOP after current image: This has meaning
only if there is a sequence (more than 1 image) in progress. In that
case, it will finish the current image (finish the requested exposure
and read/write) and then it will come back to idle (stopping the
sequence). STOP NOW : This has meaning only while exposing. It
will stop exposing immediately (closing the shutter) and read/write
right now. Then it will go back to idle (so it will stop any ongoing
sequence also). If this is done, the image headers will report the
actual exposure time done on the EXPTIME keyword (so OEXPTIME has the
originally requested value, and EXPTIME has the real one. If not
stopped, those two values will be coincident).

7.- Auxiliar GUIs buttons and quit/abort: abort:
this very small, square button is located almost on the bottom-righ
side of the image (above STOP NOW) is really hiding two "dangerous"
buttons. When pressed, two new buttons will appear: ABORT and QUIT.
ABORT: this will cause to abort any ongoing activity and will
NOT SAVE ANY DATA. It will just stop. The RED side can be aborted
does not matter what is going on (exposing or reading), but the BLUE
side can only be aborted while exposing - so in the BLUE side the
button will be disabled while reading (no aborts are accepted)-.
QUIT: this will cause to quit the GUI and shutdown the
correspondent server. This should not be done unless really
necessary.

The rest of the buttons (binning & ROI, headers,
display, temp, lamps, sync) will open auxiliary windows for
different settings as follows in section C;

2. The Turret GUI

Turret GUI

The Turret GUI is very easy and intuitive to use. It completely replaces the old blue DBSP control box.
At the top are the arc lamp controls. Simply click on the lamp you wish to use. When a lamp is on, the lamp button
turns bright green. You may have as many lamps on as you want. The Dueterium and Fe-Ar lamps will turn orange while warming up
and then turn bright green when lit. Please remember to click off the arclamps when they are not needed. They have limited lifetimes
and are a pain to replace.

Below the lamps are the four pull down menus that control the aperture, the red side filters, the blue side filters, and the Turret optical path. To make a change simply pull down a menu with the mouse and select by putting the mouse over the menu item and letting go.
The aperture and filter selections are listed above. The Turret choices require a little more explanation. The actual Turret, is a disk that moves mirrors around above DBSP. The purpose of the Turret is to give the observer a way to change the optical path so that they can view the science target (aperture), the arclamps (lamps), a wider target field (sky), and nothing (closed). By selecting aperture the observer will be observing the slit in the FLI camera or the center field Xybion camera (whichever has been selected). By selecting arclamps the observer will be sending calibration light down the DBSP slit. Selecting sky will give a wider field of view to the FLI or centerfield Xybion. This option might be useful for TOO obsevations with FLI, or help identify the proper field when the aperture field is too small.
The closed position is never used.

If for some reason the Turret GUI freezes or locks up, click the red QUIT button at the bottom of the GUI. To restart the Turret GUI open the DBSP folder that normally lives behind the Blue MAIN_GUI. In that folder you will find a Turret icon, double click the icon and the Turret should come back up. See or call, Jeff or Rick if there is strange Turret GUI behavior.

(C) AFTERNOON OF THE FIRST NIGHT:
DBSP Auxiliary GUIs

1. Binning and Region Of Interest (ROI)

This window allows you to select any single Region of Interest
(ROI) on the chip and/or change the x and/or y binning factor. As in
the Main GUI, it has light blue on the status area, and dark blue on
the control area.

Original
Geometry:

The upper part shows the geometry of the array, where: Pres:
prescan pixels. Data: Data area of the CCD. Overs: overscan
pixels. amps: total amplifier on the X or Y direction. Total
size: shows the total size that the image would have if using
full size, calculated as (Pres + Data + Overs) * amps, in the X
direction. (Data) * amps in Y direction (no prescan or overscan area
is used on Y).

Readmode: The upper left yellow is actually a control. It
shows the currently selected read mode, and by clicking on it the
mode can be changed.

The BLUE side supports left (shown on the image), right, or
lowerboth (right and left) amplifiers. The RED side only supports
left amplifier.

Current Status:

Shows the current status of the geometry, and allows (bottom part)
to change it. Note that Prescan and Overscan size cannot be
changedfrom the GUI, and that's why on the bottom area
the "Total size" stated for both columns (X) and rows (Y)
corresponds only to the Data area. Read Time: Shows the total
read time for the currently selected geometry. The calculation
includes ROI, binning and readmode. show: If selected it will
show, on the correspondent Real Time Display the ROI selected, as a
blue (BLUE side) or red (RED side) thick line. This is just a quick
guidance to the area that has been chosen.

ROI: START: COLS, ROWS: starting pixel in x and y
coordinates. The lower left corner corresponds to pixel (1,1).
LENGHT: COLS, ROWS: total size on X and Y. The image area of
the ROI will be then: [Xstart, Ystart: (Xstart+Xlen), (Ystart+Ylen)].
OK: go select the chosen area. full: selects the whole
CCD as ROI (full frame). This is equivalent to enter manually the
full frame values.

The system can be set to start with a pre-selected ROI. For
handling this, there are two buttons: set to default: Use the
currently selected ROI as the default, starting value. If this is
done, the next time the system starts it will start with this ROI as
a pre-selected value, and the next time the get default button is
used it will restore to these values. get default: if a change
was made, this button will restore the pre-selected default value.

Blue Camera (CCD23) note July 2006; It has been determined that
the chip y-axis (4096 pixels) has vignetting. The safe range starts
at row 575 and goes thru row 3400.

The
system can use Ximtool or DS9 (SAO image) as Real time displays.
These image tools need to be started independently; this auxiliary
only allows to set a couple of parameters from these devices. There
are separate displays for the BLUE and the RED sides. Usually the
daycrew or instrument support will start Ximtool for Blue and Red RTD
before you arrive. Note: the RTD displays are not meant for reduction
or analysis. Doing anything in the RTD windows tends to crash them.
For detailed image analysis at the control room workstation, ssh to
dbsp@dbsp and start a DS9/iraf session independent of the RTD.

RTD Settings GUI

display: enables or disables the Real Time Display. If
enabled, it will display the image while it is being read (in "Real
Time"). If it is disabled, the image will not be displayed
automatically. The rest of the buttons will be disabled only if
display is enabled. autoscale: If enabled, the RTD will select
automatically the upper and lower values to be mapped. If disabled,
the user can enter the desired values (z1 as the lower, z2 as the
upper) for the display mapping. z1, z2: the user-selected
values for the mapping. These fields will be enabled only if
autoscale is disabled. scaling type: type of scaling desired.
It can be: unitary, logarithmic or linear (usual). current:
these are status only. They will show the current z1 and z2 being
used for the mapping. If autoscale is enabled, they will show the
values auto-selected on the display, if autoscale is disabled, they
will show the use-selected values on the z1 and z2 controls. For
first time users don't worry too much about manipulating the Real
time Display, it's pretty much stand alone.

3. Custom Image Headers

This window allows the users to
add/delete/edit any "custom" keyword for the image FITS
headers

Headers
GUI:

The table shows the current custom
keywords. Any of those can be changed or deleted, or new ones can be
added. If the user selects a line with the mouse, it will
automatically fill the fields on the controls (see below) with that
values. This values can be entered manually also.

Below the table there are 3 string
fields, and 1 Type control. KEYWORD: the name of the desired
keyword. Value: the value for the desired keyword. If the type
is not specified, it will assume type string. Type: here the
type can be selected. STR: String. U8: unsigned 8 bits.
I8: signed 8 bits. U16: unsigned 16 bits. I16:
signed 16 bits. U32: unsigned 32 bits. I32: signed
32 bits. FLOAT : 32 bits floating point. Comment: comment
to appear on the comment area of the keyword header.

Then, there are two buttons. Delete:
It will delete the specified KEYWORD. If no keyword with that
name is found, it will have no effect. Apply: apply the
changes. If the specified keyword does already exists, it will modify
it with the new values (specified in the Value and Comment controls).
If the specified keyword does not exists, then it will be added.
After the changes are made, those keywords will become "default",
in the sense that the system will start with those values everytime
afterwards (the changes are actually stored in a header's template
file).

ask for update:NOT CURRENTLY
IN USE

4. Detector Temperature

This
small window is only for monitoring the detector temperature
purposes. It is generally left on next to the Main GUI so that the
Palomar staff can log dewar temperature with LN2 fills. If it annoys
you, close it.

Detector temp. GUI: If the
temperature falls outside the allowed limits (usually around
[150,170] Kelvin degrees), the trace will turn red, and the LED will
blink. This serves only as an alarm. If you see this happen, notify
somebody on the Palomar staff. The window updates every 60 seconds,
so if you are restarting the system, you may see blinking lights or
the wrong colors for a minute.

5. The Lamp Controller

This window controls the
Prime Focus dome lamps.

Lamps
GUI: The HIGH-lamp and LOW-lamp, are flatfield lamps that project
from Prime Focus up to a painted square on the dome when the
telescope is pointed to the zenith. The ARC lamp is a Mercury line
standard lamp which was installed for the COSMIC spectrographic
multi-aperture mode. COSMIC has no internal calibration lamps. Most
DBSP users use the internal wavelength calibration lamps and not the
dome ARC lamp.

Operation is simple, push the button
with the mouse and the lamp goes on. To turn off a lamp, toggle the
button again with the mouse. The display box below the lamp buttons,
give the "on" status.

6. Synchronization Interface (Blue side only)

This
Window is particular to the BLUE side, which acts as a "master"
when the system is run synchronized. For more information on this
please read the general explanation.

Sync GUI: This window allows you to synchronize or
un-synchronize both RED and BLUE sides. And to set what the user
wants to be synchronized. The Systems table on the left of the GUI
shows what systems are available. For DBSP there are only two
systems: DBSPBLUE and DBSPRED (for BLUE and RED sides respectively).
On the right side there are the actual controls for this GUI.

synchronize: If enabled, both systems are synchronized. If
disabled, both system are un-synchronized, which means that both
sides can be run as totally independent systems. When the systems are
synchronized, the synchronized LED will turn green, and a check mark
will appear in front of the DBSPRED entry on the table.

The rest of the controls are enabled only if synchronize is
enabled. The fact that the systems are synchronized implies this
aspects:

- Shutter open: shutter will be opened at the same time (BLUE GO
button)

- Exposure will be Paused/Resumed/Aborted/Stopped on both sides
(BLUE Pause/Resume, Abort and STOP NOW buttons)

- Sequence will be stopped at both sides (BLUE STOP after current
image button)

- object and observer will be the same on both sides (specified on
the BLUE object and observer controls)

Besides these basic aspects, there are some other parameters than
can be synchronized if desired. This is the usage of the rest of the
controls on this GUI. add prefix to basename: If checked, it
will add a prefix to the images of both sides (b_ for BLUE side, and
r_ for RED side), so now the final image name will appear as
<prefix><basename><image_number>). directory: If
ON, both images will be written on the directory specified on the
BLUE GUI (image path control). basename: If ON, both images
will have the same basename (BLUE basename control). numbering:
synchronized: The image number will be the same for both sides
(BLUE image number control). unsynchronized: numbering is kept
independent for both systems. num of images: If ON, the number
of images of the sequence will be the same for both, set by the BLUE
number of images control. exptime: If ON, the exposure time
for both sides will be the same (BLUE exptime control).

Polarimeter
checkout;

(Jeff Hickey
Aug. 17, 2006)

The old SAM polarimeter commands have been replaced by a new GUI. The new polarimeter GUI may be found after you start the VNC from the control room workstation. On the VNC window look for the DBSP folder. Open the DBSP folder by double clicking on the icon. The folder may be hidden by the Blue camera Main GUI, so look behind it. In the DBSP folder you will see an icon for the polarimeter GUI, double click that icon. The polarimeter GUI is shown below. The GUI operation is simple. First press the "Pol. Init." button, this initializes the polarimeter. Next press "CA Home" and "PA home". The GUI should now show "0" for PA angle and "HOME" for the cal position. See the table above for the proper position angles to get
the Stokes parameters you desire. Changing position is easy, simply type in the angle you want in the "set PA" window and hit return. Changing the Cal location is also easy, type "HOME", "UV", or "IR", for the three Cal positions. To check position click on the "PA read" and "Cal read" buttons. The "current PA offset" window should always read "0" at startup. As of 8/17/06, I have only tepid understanding of how PA offset is used, I belive it is a clibration offset used after observing polarization standards. I will update this document when I find out more.

Taking arc
images with DBSP will only show that the beamsplitter is in place. To
test the polarizer calset positions, and the Stokes angles,
you will need to take dome flats. The arc lamps are not in the
polarimeter optical train. If you are unfamiliar with turning on the
highlamp and opening the mirror cover, ask the daycrew or the support
astronomer. All calset and PA commands echo position
numbers to the GUI "current" windows, which should tell you that moves have been
made. As a final check, the observer should observe a polarization
standard star to confirm that the correct angles and polarizer
elements are indeed in place. For more polarimeter information see the Overview section of this web manual.

IMPORTANT NOTES:

- if directory, basename and numbering are all synchronized, the
system will check automatically add prefix to basename in order to
avoid the images to override each other. In this case the images will
be written as:

BLUE image: <imageg path>/b_<basename><image_number>

RED image: <image path>/r_<basename><image_number>

- if directory and basename are synchronized, but numbering is
unsynchronized, it is the responsibility of the user either to check
adding the prefix, or to keep the numbering distinct enough to avoid
confusion.

OBTAIN TEST FRAMES: (to see where spectrum hits the chip &
set your chip readout area on the ROI GUI, see #1 in this section)

Perform the following procedure for each camera in use:

Turn on the appropriate toggle
switch on the box labeled COMPARISON LAMPS on the DBSP control box:
He, Ne, Ar are generally good for the red side, hollow cathode
(Fe-Ar) for the blue, Hg or He if you want only a few lines; an
incandescent lamp may be used for flats, but most observers prefer
dome flats. Most lamps take just a few seconds to warm up, but the
hollow cathode (Fe-Ar) lamp takes 20 or 30 seconds. It's OK to leave
lamps on for 10 minutes or so, but not for an hour.

To view these internal lamps,
select SKY with the rotary switch on the control rack sitting on the
guider desk [in SKY mode, the on-axis guide camera directly views
the sky, and the pickoff mirror blocks sky light or outside light
from reaching the spectrograph, but allows viewing of internal
comparison lamps; in SLIT mode, the on-axis guide camera views the
sky in reflection from the polished plates of the slit].

Make a single-camera CCD exposure
byWith 1200 l/mm gratings, typical exposures are 1 sec. on the
blue side (more for the Fe-Ar ~20 sec.) and 3 sec. on the red.

Check that bias levels (dark
intensity) are about 5500 counts for the Red camera CCD21, and 3000
for the Blue CCD23;

Move the cursor to the edges of the usable field to be
retained when you trim the display, and write these coordinates down
because they will be inputs to the ROI GUI . Grating changes and
Polarimeter use, moves the spectrum around on the chip. Take some
images, and apply the desired ROI changes, and take some more
images. Remember that the smaller the area read out, the shorter the
read time.

(D) AFTERNOON OF EVERY NIGHT: FOCUS,
FLATS, BIAS...

OTHER AFTERNOON SETUP TASKS:

[NOTE that the following #1,
#2, and #3, should already be done by the Palomar staff. If you have
a concern contact the daycrew or support astronomer. Please do not
make any changes without help.] Examine spectra to see that the
images of the slit form vertical lines on the screen. If you find
that the blue camera has slit images turned clockwise, then turn the
dewar in its mount (counter)clockwise to correct; if the red camera
slit images are turned clockwise, turn the dewar (counter)clockwise
in its mount [I think.]Note: a quantitative approach is
effective...derive the tangent of the offending angle by the ratio
of x-pixels offset to y-pixel range seen on the display unit, and
match this with a correcting angle whose tangent is the amount of
travel of the dewar-rotating micrometer, divided by the 4"-inch
radius at which this micrometer is mounted. Or just take images and
make moves until you get it right.

Check that the center wavelength
is on pixel 512 (or ~2000 CCD23) to the tolerance you require;
otherwise, tweak the gratings.Don't
forget to use the additional numbers provided by the

CALCULATOR CAVEAT: the resolving power returned by the
calculator uses resolution per pixel, not per slitwidth like the
other quantities given (hence this resolving power does not change
with slit choice). Also as of 3/04, the grating calculatior does not
work well for Netscape 7.

Check the focal adjustment on the
red side; set it as a function of ambient (dome) temperature by
following the instructions taped to the side of the DBSP instrument.
Be careful not to grasp the indicator dial while adjusting, as it is
held by only a set-screw...there is very little backlash in this
adjustment, but it is probably best to approach from the same
direction (lower numbers) each time;

Check the focal settings of the
two collimators: arc-lamp images with a 0.5" slit should give
~ 3 pixel FWHM on the blue side, and ~< 2 pixel FWHM on the
red. Also it is important to note that the red camera is a lensed system. For the low dispersion (158,316) gratings there is significant focus error associated with wavelength. For example, if you focus in the center of the 158 ln/mm grating, you can expect a focus FWHM in the center of the chip ~1.5 pixels but see 4 or 5 pixels at the extreme red and blue end of the CCD.

The collimators have lots of hysteresis ("backlash"),
perhaps 10 units, so be sure to approach any given setting from the
same direction each time (from lower numbers, by editorial fiat)...
(In practice, spectra are fairly insensitive to collimator focus,
and the optimum range is fairly broad. The following table
nonetheless provides a rough guide); If you are alone, focusing
means running up and down the ladder to make adjustments in the Cass
cage. If you don't need the exercise, ask for help from Rick or
Jeff. We will be happy to adjust the collimator focus, while you
take focus images. There is a microphone/speaker system between the
Cass cage and the control room so that we don't have to run up and
down the ladder.

COLLIMATOR FOCUS
(1 digit = 1905 mm [a])

Collimator:

Blue

Red

Focus for parallel light:

450

750

Focus for good optical performance:

390-510

690-810

Total focus range:

250-600

690-1070

[a] (larger numbers move image plane further from
telescope)

Take BIAS frames. In the Main GUI
set the exptime to 0, set the obj. type to bias, set
the basename & comments to whatever you like, and take 10
or so biases.

If you like to take DARK frames,
set the exptime to whatever, set the obj. type to
dark, set the basename & comments to whatever you like,
and take as many as you need.

Take FLATS (flatfielding
frames)...either TWILIGHT FLATS on the evening sky or DOME FLATS
after the lights are turned out in the dome at 4 PM. Twilight flats
are a bit tricky to get a decent number of counts, and must be done
just as the sun sets to get the blue side right. Dome flats involve
pointing the telescope to an illuminated spot on the dome, opening
the mirror cover, and exposing. Note that dome flats can have an
emission line around 6708A, which, when used in data reduction, can
create a spurious absorption line at 6708A in spectra. Flats may also
be done using the internal incandescent lamp (not recommended) and
following the procedures outlined below for obtaining comparison lamp
spectra.
TAKING DOME FLATS (the popular choice): Please ask for help the
first time you do this.

make sure lights are out in the
dome;

have night assistant or crew
point the telescope at the illuminated patch at the zenith used for
dome flats;

open mirror cover, using switch
at night assistant's console;

open the Lamps GUI, select
HIGH to turn on the
high-intensity dome-flat lamp (select LOW to turn on the
fainter flat-field lamp; select OFF to turn off all lamps);

On the Turret GUI pulldown the turret menu and select aperture
allowing
light through the slit;

set the exptime, obj. type,
basename & comments, and take an exposure.

take a few
short exposures to calculate a desirable number of counts (remember
the shutter is unreliable under 1 second, the red side saturates
~32k, and the blue at ~65k);

to take a series of exposures,
enter your value into the number of exposures box;

remember to
select OFF in the Lamps GUI when you're done;

make sure telescope mirror cover is closed;

(E) TAKING DATA ON THE TELESCOPE:
FOCUS, FLUX STANDARDS...

Tell the night assistant the
desired "ring angle"...the orientation (position angle) of
the slit on the sky, in degrees east of north.

Focus the telescope on a star (you
will need to repeat this once or twice during the early evening as
the temperature changes):

Make sure the Turret is at aperture.
(this allows the center field camera to view the slit and
surrounding field stars reflected from the slit blades, and lets
telescope light into the spectrograph);

use the hand paddle to adjust
telescope focus until stars in guide camera field appear sharp
(guide camera and DBSP are parfocal); there is a readout of
telescope focus in mm on the RA, DEC display screen; OR there is a
automated focus box on the FLI camera GUI. Ask the night assistant to give you a demonstration.
The FLI camera documentation (not written as of 6/07) will also have details.

on your first visit (or if you
are not inclined to micro-management) ask the night assistant
attend to the telescope focus during the night;

If you are doing spectrophotometry
the night assistant can call up a suitable source from a
computerized list of spectrophotometric standards compiled by Gunn.
You may wish to do two or more standards during the night,
particularly if accurate flux calibration is important to your
experiment;
There is also a new standards GUI that can be run for all 200" cameras. On Vulcan load your
target list into a directory you make in /home/user. Then type "ptic target.lis" where target.lis is your list file name.
The GUI will appear, and whatever star you select you can quickly find nearby standards from several lists.

(F) TAKING DATA ON THE TELESCOPE:
SCIENCE OBJECT...

Important note on the red camera; The red camera does not continuously wipe the chip when in idle mode. When the camera has been idle for any length of time, take a quick bias frame to clear the chip!

If you need to, take comparison
lamp for wavelength calibration before (and after) any exposure on
the science object:

Select lamps on the Turret GUI

Turn on the desired lamp with
mouse clicks on the desired lamps.
Fe-Ar is good for Blue, He, Ne, and Ar, are good for Red...Fe-Ar takes
more than 10 seconds to warm up; neon, just a few seconds;

take an exposure using, use about
30 seconds for Blue, 1 second for Red;

turn off the comparison lamp
(don't leave it on for hours);

select aperture again
on the Turret GUI turret menu, to prepare for object
exposure;

As mentioned above use IRAF and
DS9 to display your images.

Set up the guider (consult night
assistant and guider documentation, Appendix C);

Observe your science object:

set the ring to the desired
position angle for the slit on the sky, measured E of N;

put your position reference star
(from which you will offset to your science source) onto the center
of the slit and have the night assistant "X" the
coordinates;

put the cursor on the slit center
as well;

ask the night assistant to offset
to science object;

fill in the desired header,
exptime, obj. type, basename & comments, information;
and take an image.

use the pause or stop buttons in
the Main GUI to alter exposures or sequences, see above #6 in Main
GUI.

Take comparison lamps if you need
precise wavelength calibration after this exposure on the science
object (repeat steps 1.1 to 1.5 at top of this section, as were done
before science exposure).

Repeat the larger cycle of major steps 1 to 5 for each source
position.

(G) END OF THE RUN, DATA
TRANSFER/MEDIA BACKUP

Your files are saved to /rdata/DBSP on the DBSP computer.
Sftp file transfer can be easily done from this location. See the Instrument Support Engineers for relevant passwords.

There are DVD burners on each of the control room workstations. They are easy
to use "drag and drop" burners. Ask for help the first time
you use them, and take notes. Supposedly, the DVD burners will burn
all flavors of DVD. Some testing yet needs to be done to prove that
all types of DVD will work on all these workstations. When you are
happy with your transfer and/or DVD backup, please be a good
Astronomy neighbor and delete your raw & reduced files. You
are responsible to supply your own media (DVD, -R, -RW, etc.)

APPENDIX
(A): Grating Installation

[Note; 3/04; Appendices A & B are somewhat out of
date. The day crew and support astronomers currently take care of all
grating installations or adjustments. This section is still included
as a reference and training document for the Palomar staff. If
something does not look correct on your test spectra, contact the day
crew or support astronomer/engineer for help.

Requested gratings are installed by the day crew as part of
instrument setup. Actual changes take roughly 10 minutes per side.
Note that gratings can go in either side, but RED/BLUE grating
rotators are not interchangeable.

If you intend to replace the
grating, find the empty drum into which it will go, and the drum
with the new grating you want to install; these are stored in the
cabinet near the door leading from the dome to the elevator area.
Set the drum on the wooden desk nearby, and put out the Allen wrench
with the large handle, too;

Loosen the single lock-screw at
bottom center of the grating rotator;

Move the grating angle to 0
degrees and retighten the lock-screw;

Loosen the 4 symmetrically-placed
screws holding the grating rotator in place (they are captured, so
can't fall out). The 4 screws have black knobs, and are the
outermost four in the right-hand diagram below;

Holding the two handles, gently
slide the rotator and attached grating out, toward you (careful,
they are quite heavy...beginners use two hands);

If it's the one you want, slide
the grating back in and retighten screws; otherwise, carry it down
the ladder from the Cass cage and put it in the drum on the wooden
desk, then secure it with the four lip clamps;

Use the Allen wrench with the
round handle to loosen the screw in the center of the black knob on
the grating rotator; when the rotator is free, put it on the
replacement grating and tighten;

Take the reloaded rotator back up
to DBSP and reattach;

Grating cell in drum (left), grating rotator
(right)...

APPENDIX
(B): Setting Grating Angles

CALCULATOR CAVEAT: the resolving power returned by the
calculator uses resolution per pixel, not per slitwidth like the
other quantities given (hence this resolving power does not change
with slit choice).

Refer to the right-hand side of the figure immediately above,
showing a grating rotator as it would look when installed on the
spectrometer:

Recall that grating angle = 0
corresponds to having the face of the grating perpendicular to the
beam incident from the collimator (grating face horizontal with
telescope at zenith);

Recall that increasing the grating
angle involves tipping it toward the camera projecting out of the
instrument at an odd angle...this is the counterclockwise direction
for both blue and red sides;

Release the clamp at bottom
center;

Set the angle by turning the black
8-pointed knob, and read the grating angle on the vernier scale
viewed through the round magnifier...you can move the magnifier left
and right if you first push down on the spring-loaded bar on which
it is mounted;

To read the vernier: see where the
zero line on the fixed outer circle, at top, points on the scale on
the inner circle, which is marked to the half-degree; to determine
the number of arc minutes above (or below) that nearest half-degree,
look to the right (or left) and take the number on the outer circle
that lines up with any line on the inner circle (standard vernier
procedure); to the right is 0 - 30 minutes and to the left is 31 -
59 minutes. The left read is confusing because you are subtracting
from the next full degree. For example, say you have to set the
vernier to 24 degrees 45 minutes. Set the zero line to 25 degrees
and the slowly adjust the zero line to the left until any inner
circle line matches up with 15 minutes "left". You are now
at 24 degrees 45 minutes, because you subtracted 15 minutes from 25
degrees. Ask for help, it will make much more sense when you
actually do it with supervision.

Tighten the clamp while holding the knob steady (or it will
move).

APPENDIX (C): Brief Primer on
Guiders

The old offset guider
has been supplanted (in the last century) by the "Palomar
Autoguider" developed by Martin Shepherd and Palomar staff. The
Autoguider has comprehensive documentation of its own (see Palomar
Autoguider); we summarize the main points here.

The night assistant can help you with the finer points and
getting set up. Some observers prefer to have the night assistant
run the guider. The choice is up to you, but don't hesitate to ask
for help if you get stuck using the guider. BE CAREFUL, the guider
cameras are image intensified, and can be damaged with over
exposure. The main controls that you will use are:

ENABLE button at upper
right...turns on the guider; clicking on it (with left button of
mouse) toggles it ON/OFF, and it changes color accordingly...yellow
means it's OFF (i.e. caution, you're not guiding);

INTENSIFIER GAIN slidebar, 1/3 of
the way down on right side...turn it down (via click-and-drag to
left) when slewing, as you would to protect any camera;

FRAMES PER INTEGRATION and INTEGRATIONS TO AVERAGE
slidebars, about 1/2 way down on right side...the product of these
is the number of (30 Hertz) frames that are averaged in each update
of the display; you might adjust these according to seeing and
brightness of the guide star;

Most of the many other controls may be ignored and left the way
you found them, or the night assistant advised you to set them. The
on-screen green box within which the guide star position is
calculated (by, eg., a centroid) may be resized by clicking and
dragging on its edges. The crosshairs inside the box display the
current position solutions in x and y; the crosshairs outside the
box disappear when the solution is not found.

NOTE: All FIGARO commands are obsolete as
of spring 2005. Please forget them.